The present application relates to a semiconductor structure and a method of forming the same. More particularly, the present application relates to a semiconductor structure in which a hydrogenated crystalline silicon region is disposed between a channel material of germanium or a germanium tin alloy and a contact structure, and a method of forming the same.
For more than three decades, the continued miniaturization of metal oxide semiconductor field effect transistors (MOSFETs) has driven the worldwide semiconductor industry. Various showstoppers to continued scaling have been predicated for decades, but a history of innovation has sustained Moore's Law in spite of many challenges. However, there are growing signs today that metal oxide semiconductor transistors are beginning to reach their traditional scaling limits. Since it has become increasingly difficult to improve MOSFETs and therefore complementary metal oxide semiconductor (CMOS) performance through continued scaling, further methods for improving performance in addition to scaling have become critical.
Germanium and germanium tin alloys are examples of high carrier mobility channel materials which are attractive for use in complementary metal oxide semiconductor (CMOS) logic devices at the 7 nm and beyond technology nodes. These materials require low processing temperatures due to material instability. Moreover, forming contact structures on n-doped germanium is a well known problem due to low density of the dopants and high contact resistance. There is thus a need for providing a method of forming a semiconductor structure including a channel material of germanium or a germanium tin alloy and a contact structure that circumvents the problems mentioned above.